Controlled nucleation and growth for the dendrite-free zinc anode in aqueous zinc-ion battery

Due to the advantages of environmental friendliness and low cost, aqueous zinc-ion batteries have attracted extensive attention in years. However, the invertibility of zinc anode is seriously affected by the growth of zinc dendrite during the process of cycle. Herein, the dendrite problem under low current density is alleviated by the introduction of the ZIF-8 annealed at 550 ℃ (ZIF-8–550), and it serves as a galvanization host by homogenizing the Zn nucleation sites. Then the invalidation problem of the host under high current density is subsequently pointed out and solved by controlling the growth process. H3BO3 and Na2SO4 additives are introduced to the electroplating solution to reduce the initial galvanizing rate and improve the reversibility at high current density. As a result, the ZIF-8–550 host with galvanic additives is highly reversible and stable during the Zn plating/stripping process, and it displays a voltage hysteresis as low as 90 mV after cycling for more than 2000 h under an extreme pre-galvanizing condition of 10 mA cm−2 and 10 mA h cm−2. This work can also provide a useful reference for the development of dendrite-free zinc anode.